Chapter 4: The Structure Of An Atom

Front 1

Daltons Atomic Theory

Back 1

Scientific research that uncovered the the mass ratios of each element involved in reactions. the theory determined the deffinition of an atom.

Front 2

atom

Back 2

the smallest partical of an element that retains the proprerties of the element.

Front 3

cathode ray

Back 3

this accidental discovery eventualy lead to the invention of the television. a ray going through a tube (radiation)

Front 4

electrons

Back 4

negatively charged particals that are a part of all forms of matter.

Front 5

nucleus

Back 5

a tiney dense reagon in the atom that holds most of the mass of the atom holding most of all of its postiavely charged particals.

Front 6

proton

Back 6

a subatomic partical carrying a charge equal to but opposite of an electron.

Front 7

neutron

Back 7

a subatomic partical that has a mass nearly equal to that of a proton, but carries no electric charge.

Front 8

atomic number

Back 8

the number of protons in an atom

Front 9

isotopes

Back 9

atom with the same number of protons but different numbers of neutrons

Front 10

mass number

Back 10

the sum of the atomic number and neutrons in the nucleus.

Front 11

atomic mass unit (amu)

Back 11

is defined as one-twelfth the mass of a carbon-12 atom, a mass of exactly 12 atomic mass units.

Front 12

radioactivity

Back 12

substance the emmits radiation

Front 13

radiation

Back 13

the rays and particals emitted by radioactive atoms.

Front 14

nuclear reaction

Back 14

a reaction that involves a change in the atoms neuclus.

Front 15

radioactive decay

Back 15

unstable nuclei lose energy by emmiting radiation in a spontanious process.

Front 16

alpha radiation

Back 16

made up of alpha particals

Front 17

alpha particals

Back 17

contains two protons and two neutrons, and thus has a 2+ charge.

Front 18

nuclear equation

Back 18

created as a result of alpha decay.

Front 19

beta radiation

Back 19

the radiation that was deflicted toward the positvely chararged plate

Front 20

beta particles

Back 20

an electron with a 1- charge.

Front 21

gama ray

Back 21

the third kind of radiation is a high energy gamma radiation